Question about Cobra 29 LTD CB Radio

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No antenna lite when transmitting

It seems when iam in the ohio area i don't get an antenna lite when trans mitting. i had one when i was in the tennesee area or down in that area, but when i was in the pa. area or when i got back to the ohio area, i lost the antenna lite when i transmitted. this could be just a fluke, but i want to find out how to calibrate the swr on the radio. is it something in the radio that i have to adjust, like how i calibrate it on the cal button, or is it something with the antennas. the antennas were on the truck. it is a freightliner antenna setup. i think one antenna is a fire stick and the other is a k40 with 2500 watts capibility. ican adjust the top of the k40. i am not sure about the fire stick. can you help me understand and learn to fix this problem myself? thanks for your help. steve

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Antenna light should be a warning indicator for high VSWR..... simple rule of thumb for CB antenna.... the lower the frequency "channel" the longer the antenna length, higher the frequency "channel" the shorter the antenna length. Your vehicle is a ground plane, where you mount the antenna will also affect its operation and tuning. A properly tuned antenna will have lower reflection on the midband channels and gradually rise as you near the upper and lower end of the band. Some base loaded antennas will be noticably narrow in bandwidth, if you have that problem then tune it for the channel you use most!
K40 has always been good for easy tuning and band coverage, center it on the vehicle top for good omni coverage!
PS... always make sure your connectors are secure, a loose shield will ruin your day when adjusting SWR!

Posted on Dec 22, 2008

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Freightliner uses mutiplex

Posted on Oct 18, 2009

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Both antanas should be the same (matched) read mfg instruction on how to set swr make sure ant. cable is not kinked mashed nicked or coiled up

Posted on Dec 24, 2008

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tune SWR

there could already be some damage to the final transistor already, it may be why the light stays on. Tune the antenna according to the article and then if the light stays on again, there may be something wrong with the radio, or the warning light is not adjusted correctly.

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